The first is by Dr. Amr Abouleish titled “Try and hold your breath while reading this!”
The second is “A Mixed (Long- and Medium-chain) Triglyceride Lipid Emulsion Extracts Local Anesthetic from Human Serum In Vitro More Effectively than a Long-chain Emulsion,” by Weiming Ruan and Deborah French.
The first piece gives an anesthesiologist’s take on magician David Blaine’s world record setting attempts at holding his breath (as opposed to holding someone elses?) for more than 17 minutes. You can watch the TED Talk in which Mr. Blaine instructs audience members in the special preparation needed to hold their breath for more than three minutes after breathing “normal” or upwards of 17 minutes after huffing pure oxygen.
Dr. Abouleish poses the following question to his new anesthesiologist residents when discussing the relationship of end-tidal CO2 and respiration. “If your oxygen saturation is 100% and you hold your breath, what would your oxygen saturation be when you have to breathe?”
Of course all magicians know the answer to this but non-magic oriented medical residents need to be reminded of the relatively slow decline in oxygen saturation experienced by pre-oxygenated patients under general anesthesia.
We agree with Dr. Abouleish’s praise of Blaine’s talk. Those in the audience were able to hold their breath for as long as three minutes or more. Check it out for yourself and abide the constant warnings that this is not a skill easily acquired and one should never try this under water. The chance of passing out is high and because the risk of drowning whilst underwater is directly proportional to being conscious, you could, in the medical parlance, “konk out and die.”
The comments to Dr. Abouleish’s article are also instructive. There is general agreement that Mr. Blaine should have sought advice from an anesthesiologist rather than neurologists.
Instructive is a comment from Dr. Gerald Zeitlin. His capitalization and grammar is taken verbatim from his post:
As you all know Dr. Abouleish is discussing apneic oxygenation.
Watching David Blaine do his 17 minutes was fantastic – but what an incredibly wasted opportunity for science.
As we all know, HE SHOULD HAVE CONSULTED AN ANESTHESIOLOGIST!
Neurosurgeons “Don’t know nuffin’ ” about respiratory physiology. Why did Blaine not have an arterial line for his record attempt – then we’d have known what his arterial pCO2 was after 17 minutes.
Of course we all know that, at rest, during apnea the pCO2 rises between 3 and 5 mm. Hg per minute.
I failed math in Kindergarten but I think 17 times, let’s say 4 mm. Hg = 68. So, approximately he was at 108 mm.Hg pCO2.
As WE (anesthesiologists) know that level has mild to moderate anesthetic properties. I bet if you Emailed Dr. Eger he would know what the MAC of CO2 is.
We would love to meet Dr. Zeitlin. He is our kind of guy.
The second article of magic merit in the February 2012 edition of Anesthesiology, attempts to the answer the age old question, which extracts local anesthesia better, a “mixed” triglyceride lipid emulsion or a long-chain version?
Houdini’s correspondence with Kellar on this issue springs to mind.
In 1921, Houdini expressed amazement that Kellar would still believe long-chain triglyceride lipid emulsion alone could extract local anesthesia better than say, medium or short chain emulsions.
Houdini’s concern about medicine and fundamentally sound research is noted in a great post over at The Chemical Institute of Canada’s web site, Chemically Speaking. He urged medical students to engage in real, science-based research rather than pseudoscience.
Kellar, the wise old Dean, disagreed with those taking “pot shots” (his words) at the generally accepted theory of anesthesia extraction through fatty emulsions.
“Old friend, since the introduction of lipid-related anesthetic theory, the logic of the maxim ‘like dissolved (sic) like’ has been proven out. Long-chain triglyceride lipid emulsions were good enough for my father and they are certainly good enough for me.”
Houdini, always the wise upstart retorts, “Harry, once again you completely ignore the important role pH-level (sic) play in the getting the local anesthetic in and so you miss the way to get it out.”
While not as divisive as their debate over Thurston “theft” of Houdini’s tricks, the triglyceride hubbub was a constant theme in their correspondence.
We wonder what Kellar would have to say if he were around today to read the latest developments in anesthesia vis-à-vis lipid extraction.